eszett ligature

The eszett ligature in German

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I typed the word groß in a Word document and tried to see it replaced automatically by gross, just by changing the font applied to the word. To my surprise, just one font "Showcard Gothic" did the substitution. I don't know why, but it seemed to me that this substitution should occur more often. Is there any explanation for this behavior, other than the obvious one, that this is the only way to write this word ?